by nite0wl » 2 Jul 2015 22:00
The point of serrated pins (key-pins or driver-pins) is that the serration is supposed to provide false feedback by imitating the feeling of raising a standard pin to the shearline. Serrated key-pins are combined with serrated drivers to make it more likely that you will be tricked into overlifting at least one pinstack (raising the keypin to the point at which it begins blocking the shearline). Very well made serrated pins that are well fitted to their cylinders (like American Lock's usually are) do a good job of imitating the feeling of setting a pin (some others are not so good at this and wear, weathering, and fouling can reduce their effectiveness). My method of dealing with this is after each 'set' gently probe the rest of the pin stacks, if another stack has not started binding, return to the one that you just 'set' and lift it again. This method is far from foolproof and requires a gentle touch and a good sense of the feed back that your tools produce but it works well.